When should you see a doctor about crusting skin?

A crust is dried fluid, blood or skin material on the surface. Atopic dermatitis can ooze and crust after scratching. Impetigo may produce contagious golden or honey-coloured crusts, while eczema herpeticum can cause clusters of painful blisters and crusted sores in skin affected by eczema. These patterns need different treatment.

Clean gently with water, pat dry, and avoid peeling the crust away. Wash hands after touching the area, do not share towels, and pause products that sting. Keep a note of spread, pain, discharge, fever and new blisters so a clinician can judge how quickly the problem is changing.

Arrange prompt medical review for rapidly spreading crusts, increasing warmth or redness, pus, marked tenderness, fever, or sores near the eyes. Seek urgent care for painful clustered blisters, feeling very unwell, eye symptoms, or crusting in a baby. Avoid close skin contact if an infection is possible until assessed.

Ask whether the crust is from eczema, impetigo, a viral infection or another cause; whether testing is needed; and how to reduce spread at home. Tell the clinician when the rash began, whether blisters came first, and which creams have been used.